Category M:
Motor driven vehicles, used for the carriage of passengers with:  At least four wheels or With three wheels and a maximum weight over 1 tonne (articulated vehicles of two non-separable, articulated units shall be considered as single vehicles)
M1	Passenger vehicles with up to eight seats in addition to the driver's seat.
M2	Passenger vehicles with more than eight seats in addition to the driver's seat, and a maximum weight of 5 tonnes.
M3	Passenger vehicles with more than eight seats in addition to the driver's seat, and a maximum weight over 5 tonnes.

Category N:
Power-driven vehicles having at least four wheels or having three wheels when the maximum weight exceeds 1 tonne, and used for the carriage of goods.
N1	Goods vehicles with a maximum weight of 3,5 tonnes.
N2	Goods vehicles with a maximum weight over 3,5 tonnes but not over 12 tonnes.
N3	Goods vehicles with a maximum weight over 12 tonnes.

Category O:
Trailers (including semi-trailers)
O1	Single-axled trailers, other than semi-trailers, with a maximum weight of up to 0,75 tonne.
O2	Trailers with a maximum weight of up to 3,5 tonnes, not in Category 01.
O3	Trailers with a maximum weight over 3,5 tonnes, but not over 10 tonnes.
O4	Trailers with a maximum weight over 10 tonnes.